body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background: #faf8ef;
}

#game {
    text-align: center;
}

#game_score {
    font-size: 24px;
    margin-bottom: 20px;
    display: block;
}

#game_container {
    position: relative;
    margin: 0 auto;
    background: #bbada0;
    border-radius: 6px;
    padding: 20px;
}

.game-cell, .game-num {
    position: absolute;
    border-radius: 3px;
}

.game-num {
    color: #fff;
    font-size: 40px;
}

.game-num-2 {
    background:#eee4da;
    color:#776e65;
  }
  .game-num-4 {
    background:#ede0c8;
    color:#776e65;
  }
  .game-num-8 {
    background:#f2b179;
  }
  .game-num-16 {
    background:#f59563;
  }
  .game-num-32 {
    background:#f67c5f;
  }
  .game-num-64 {
    background:#f65e3b;
  }
  .game-num-128 {
    background:#edcf72;
    font-size:35px;
  }
  .game-num-256 {
    background:#edcc61;
    font-size:35px;
  }
  .game-num-512 {
    background:#9c0;
    font-size:35px;
  }
  .game-num-1024 {
    background:#33b5e5;
    font-size:30px;
  }
  .game-num-2048 {
    background:#09c;
    font-size:30px;
  }